feat(git): add tag management and cherry-pick workflow

This update extends the Git backend and UI to support listing,
creating, deleting, and pushing tags. It also adds cherry-pick
commands with proper in-progress detection and conflict handling, and
prevents other operations while a cherry-pick is active.

- Add GitTag model, tag listing, and tag CRUD/push commands
- Implement cherry-pick start/continue/abort with status tracking
- Update UI to display tags and gate actions during cherry-pick

src/App.svelte

@@ -2,7 +2,7 @@
   import { onDestroy, onMount, tick } from "svelte";
   import { open as openDialog } from "@tauri-apps/plugin-dialog";
   import { check, type DownloadEvent, type Update } from "@tauri-apps/plugin-updater";
-  import { AlertCircle, BookOpen, Download, FolderOpen, GitBranch, GitMerge, LoaderCircle, Plus, Search, X } from "@lucide/svelte";
+  import { AlertCircle, BookOpen, Cherry, Download, FolderOpen, GitBranch, GitMerge, LoaderCircle, Plus, Search, X } from "@lucide/svelte";
 
   import TitleBar from "./lib/TitleBar.svelte";
   import AiSettingsDialog from "./lib/components/AiSettingsDialog.svelte";
@@ -29,6 +29,9 @@
 
   import {
     checkoutBranch,
+    cherryPickAbort,
+    cherryPickCommit,
+    cherryPickContinue,
     cloneRepository,
     commit,
     commitAiGenerate,
@@ -40,13 +43,16 @@
     cancelFileHistory,
     applyFilePatch,
     createBranch,
+    createTag,
     deleteBranch,
+    deleteTag,
     diffFileAgainstWorkingTree,
     compareFileToParent,
     fetchRemote,
     getStatus,
     listBranches,
     listStashes,
+    listTags,
     listCommits,
     listFileHistory,
     listRepositoryFiles,
@@ -56,6 +62,7 @@
     openRepositoryBundle,
     pull,
     push,
+    pushTag,
     renameBranch,
     rebaseAbort,
     rebaseBranch,
@@ -97,6 +104,7 @@
     GitSearchHit,
     GitStash,
     GitStatus,
+    GitTag,
     LocalModelOption,
     PatchApplyAction,
     PreparedResolution,
@@ -160,6 +168,7 @@
   let pendingClone: CloneRequest | null = null;
   let status: GitStatus | null = null;
   let branches: GitBranchInfo[] = [];
+  let tags: GitTag[] = [];
   let stashes: GitStash[] = [];
   let commits: GitCommit[] = [];
   let repoFiles: GitRepositoryFile[] = [];
@@ -260,9 +269,12 @@
   $: conflictedFiles = changedFiles.filter((f) => f.staged === "conflicted" || f.unstaged === "conflicted");
   $: hasConflicts = conflictedFiles.length > 0;
   $: rebaseInProgress = status?.rebase_in_progress ?? false;
-  $: canCommit = hasRepository && stagedCount > 0 && commitMessage.trim().length > 0 && !hasConflicts && !rebaseInProgress && !isBusy;
+  $: cherryPickInProgress = status?.cherry_pick_in_progress ?? false;
+  $: canCommit = hasRepository && stagedCount > 0 && commitMessage.trim().length > 0 && !hasConflicts && !rebaseInProgress && !cherryPickInProgress && !isBusy;
   $: commitBlockReason = rebaseInProgress
     ? "A rebase is in progress. Resolve conflicts and use Rebase continue or abort the rebase."
+    : cherryPickInProgress
+    ? "A cherry-pick is in progress. Resolve conflicts and use Cherry-pick continue or abort it."
     : hasConflicts
     ? `${conflictedFiles.length} ${conflictedFiles.length === 1 ? "conflict must" : "conflicts must"} be resolved before committing.`
     : "";
@@ -360,6 +372,7 @@
       const bundle = await openRepositoryBundle(activeRepoPath, 100);
       const previousHeadHash = lastFileHistoryHeadHash;
       await refreshBranchList(activeRepoPath, bundle.branches);
+      await refreshTags(activeRepoPath, bundle.tags);
       await refreshStashes(activeRepoPath, bundle.stashes);
       await refreshCommitHistory(activeRepoPath, bundle.commits);
       await refreshExplorerFiles(activeRepoPath, bundle.files);
@@ -941,6 +954,10 @@
     branches = prefetched ?? (await listBranches(path));
   }
 
+  async function refreshTags(path = activeRepoPath, prefetched?: GitTag[]) {
+    tags = prefetched ?? (await listTags(path));
+  }
+
   async function refreshStashes(path = activeRepoPath, prefetched?: GitStash[]) {
     stashes = prefetched ?? (await listStashes(path));
   }
@@ -1039,6 +1056,7 @@
       if (globalSearchBusy) void cancelGlobalSearch();
       activeView = "repository";
       await refreshBranchList(activeRepoPath, bundle.branches);
+      await refreshTags(activeRepoPath, bundle.tags);
       await refreshStashes(activeRepoPath, bundle.stashes);
       await refreshCommitHistory(activeRepoPath, bundle.commits);
       await refreshExplorerFiles(activeRepoPath, bundle.files);
@@ -1106,6 +1124,7 @@
       if (globalSearchBusy) void cancelGlobalSearch();
       activeView = "repository";
       await refreshBranchList(activeRepoPath, bundle.branches);
+      await refreshTags(activeRepoPath, bundle.tags);
       await refreshStashes(activeRepoPath, bundle.stashes);
       await refreshCommitHistory(activeRepoPath, bundle.commits);
       await refreshExplorerFiles(activeRepoPath, bundle.files);
@@ -1327,7 +1346,7 @@
   }
 
   async function rebaseOnto(branch: GitBranchInfo) {
-    if (!activeRepoPath || branch.current || rebaseInProgress) return;
+    if (!activeRepoPath || branch.current || rebaseInProgress || cherryPickInProgress) return;
     await runOperation(`Rebasing onto ${branch.name}`, async () => {
       applyStatus(await rebaseBranch(activeRepoPath, branch.name));
       await refreshBranchList(activeRepoPath);
@@ -1366,6 +1385,84 @@
     });
   }
 
+  async function createNewTag(name: string, message: string) {
+    const trimmed = name.trim();
+    if (!activeRepoPath || !trimmed) return;
+    await runOperation(`Creating tag ${trimmed}`, async () => {
+      await refreshTags(activeRepoPath, await createTag(activeRepoPath, trimmed, undefined, message));
+    });
+  }
+
+  async function deleteLocalTag(tag: GitTag) {
+    if (!activeRepoPath || isBusy) return;
+    const confirmed = window.confirm(`Delete tag '${tag.name}'?\n\nThis only removes the local tag, not any copy already pushed to a remote.`);
+    if (!confirmed) return;
+
+    await runOperation(`Deleting tag ${tag.name}`, async () => {
+      await refreshTags(activeRepoPath, await deleteTag(activeRepoPath, tag.name));
+    });
+  }
+
+  async function pushLocalTag(tag: GitTag) {
+    if (!activeRepoPath || isBusy) return;
+    const key = await currentCredKey();
+    const stored = await loadStoredCredential(key);
+    const credential = stored && !isCredentialExpired(stored) ? stored : null;
+
+    await runOperation(`Pushing tag ${tag.name}`, async () => {
+      try {
+        await pushTag(activeRepoPath, tag.name, credential?.username, credential?.password);
+      } catch (error) {
+        const message = errorToMessage(error);
+        throw new Error(
+          isAuthError(message)
+            ? `Sign in via the Push button first, then retry pushing tag '${tag.name}'.`
+            : stripAuthPrefix(message),
+        );
+      }
+    });
+  }
+
+  async function cherryPickFromCommit(commit: GitCommit) {
+    if (!activeRepoPath || rebaseInProgress || cherryPickInProgress) return;
+    await runOperation(`Cherry-picking ${commit.short_hash}`, async () => {
+      applyStatus(await cherryPickCommit(activeRepoPath, commit.hash));
+      await refreshBranchList(activeRepoPath);
+      await refreshCommitHistory(activeRepoPath);
+      await refreshExplorerFiles(activeRepoPath);
+      await refreshFileHistory(activeRepoPath);
+    });
+  }
+
+  async function continueCherryPick() {
+    if (!activeRepoPath || !cherryPickInProgress || hasConflicts) return;
+    await runOperation("Continuing cherry-pick", async () => {
+      applyStatus(await cherryPickContinue(activeRepoPath));
+      await refreshBranchList(activeRepoPath);
+      await refreshCommitHistory(activeRepoPath);
+      await refreshExplorerFiles(activeRepoPath);
+      await refreshFileHistory(activeRepoPath);
+    });
+  }
+
+  async function abortCherryPick() {
+    if (!activeRepoPath || !cherryPickInProgress) return;
+    const confirmed = window.confirm("Abort the current cherry-pick and return to the previous state?");
+    if (!confirmed) return;
+
+    await runOperation("Aborting cherry-pick", async () => {
+      applyStatus(await cherryPickAbort(activeRepoPath));
+      preparedResolutions = {};
+      resolveDialogOpen = false;
+      conflict = null;
+      conflictTarget = "";
+      await refreshBranchList(activeRepoPath);
+      await refreshCommitHistory(activeRepoPath);
+      await refreshExplorerFiles(activeRepoPath);
+      await refreshFileHistory(activeRepoPath);
+    });
+  }
+
   // Resolve the keychain key (host/org) for the active repo's remote.
   async function currentCredKey(): Promise<string | null> {
     if (!activeRepoPath) return null;
@@ -1783,6 +1880,10 @@
       errorMessage = "A rebase is in progress. Use Rebase continue or abort the rebase.";
       return;
     }
+    if (cherryPickInProgress) {
+      errorMessage = "A cherry-pick is in progress. Use Cherry-pick continue or abort it.";
+      return;
+    }
     await runOperation("Committing", async () => {
       applyStatus(await commit(activeRepoPath, message));
       commitMessage = "";
@@ -2201,7 +2302,7 @@
       </section>
     {/if}
 
-    {#if workspaceActive && hasConflicts && !rebaseInProgress}
+    {#if workspaceActive && hasConflicts && !rebaseInProgress && !cherryPickInProgress}
       <section class="notice conflict" role="alert">
         <GitMerge size={17} aria-hidden="true" />
         <span>{conflictedFiles.length} {conflictedFiles.length === 1 ? "file has" : "files have"} conflicts.</span>
@@ -2228,6 +2329,25 @@
       </section>
     {/if}
 
+    {#if workspaceActive && cherryPickInProgress}
+      <section class="notice rebase" role="status">
+        <Cherry size={17} aria-hidden="true" />
+        <span>
+          Cherry-pick in progress.
+          {#if hasConflicts}
+            Resolve conflicts, then continue.
+          {:else}
+            Continue when the index is ready, or abort to return to the previous state.
+          {/if}
+        </span>
+        {#if hasConflicts}
+          <button type="button" onclick={openResolveDialog} disabled={isBusy}>Resolve conflicts</button>
+        {/if}
+        <button type="button" onclick={continueCherryPick} disabled={isBusy || hasConflicts}>Continue</button>
+        <button type="button" onclick={abortCherryPick} disabled={isBusy}>Abort</button>
+      </section>
+    {/if}
+
     {#if activeView === "management"}
       <section class="repo-management" aria-label="Repository Management">
         <div class="repo-management-head">
@@ -2354,6 +2474,7 @@
           {branches}
           {localBranches}
           {remoteBranches}
+          {tags}
           {hasRepository}
           {isBusy}
           onCheckout={checkout}
@@ -2362,6 +2483,9 @@
           onCreateBranch={createNewBranch}
           onRenameBranch={renameLocalBranch}
           onDeleteBranch={deleteLocalBranch}
+          onCreateTag={createNewTag}
+          onDeleteTag={deleteLocalTag}
+          onPushTag={pushLocalTag}
         />
         <StashPanel
           {stashes}
@@ -2490,6 +2614,7 @@
           onRestoreCommit={restoreCommit}
           onPreviewCommitFile={previewCommitFileFromHistory}
           onCreateBranchFromCommit={openNewBranchDialog}
+          onCherryPickCommit={cherryPickFromCommit}
           onToggleCommitFiles={(hash) => {
             const next = new Set(expandedCommitHashes);
             if (next.has(hash)) next.delete(hash); else next.add(hash);